After many research i still can't get the starting quest needed for the knowledge(even during night(at the really good maudi budar npc)). It seem that maybe this questchain is available only after some knowledge at Illya island as the questchain seem to go to Illya after few quest; i'll update if i found what unlock this questchain for me.
EDIT:Savage rift which are needed at the really end of the questchain are currently "closed for renewal"(since august 2021) which may be the reason why the entire questline is not available.
EDIT2:I did sent a ticket to the support, and my assumption seems to be exacts, the quest is not available as of march 2022. No idea when it will be back.
EDIT3:Was doing mediah V adventure journal when i did took the knowledge needed to the "geant" guys (https://bdocodex.com/kr/npc/693/655/ )(check location on the link, he is on the top of the house), he give aswell the black scroll knowledge, no need to do a quest or whatsoever.
2024, talked to the guy on the roof, paid 15 energy for the knowledge. Didn't do any quests. Also has knowledge the evil of necromancy for another 15 energy, for mediah adventure log IV----EDIT mediah adventure log V